Zinc oxide-decorated multiwalled carbon nanotubes: a selective electrochemical sensor for the detection of Pb(II) ion in aqueous media

Journal of Materials Science: Materials in Electronics - Multiwalled carbon nanotubes, due to high conductivity, stability, and large specific surface area, have a potential ability to promote...     

CuxNi1-xO nanostructures and their nanocomposites with reduced graphene oxide: Synthesis,characterization, and photocatalytic applications

NiO nanostructure was synthesized using a simple co-precipitation method and was embedded on reduced graphene oxide surface via ultrasonication. Structural investigations were made through X-ray diffraction (XRD) and functional groups were confirmed by Fourier transform infrared spectroscopy (FTIR). XRD analysis revealed the grain size reduction with doping. Fourier transform infrared spectroscopy confirmed the presence of metal-oxygen bond in pristine and doped NiO nanostructure as well as the presence of carbon containing groups. Scanning electron microscopy (SEM) indicated that the particle size decreased when NiO nanostructure was doped with copper. BET surface area was found to increase almost up to 43 m²/g for Cu doped NiO nanostructure/rGO composite. Current-voltage measurements were performed using two probe method. UV–Visible spectroscopic profiles showed the blue and red shift for Cu doped NiO nanostructure and Cu doped NiO Nanostructure/rGO composite respectively. Rate constant for Cu doped NiO nanostructure/rGO composite found to increase 4.4 times than pristine NiO nanostructure.     

Fast determination of critical eluent composition for polymers by gradient chromatography

Gradient chromatography was applied in order to calculate the composition at elution for different methacrylates on normal phase columns. In addition the composition at elution was determined for polyethyleneoxide on a reverse phase column. It is shown that high molar mass polymers elute for a given homopolymer irrespective of their molar mass at the same eluent composition, which varies only slightly with gradient slope. In general the composition at elution in gradient chromatography is expected to be slightly lower than the true critical composition. For high molar mass polymers we found this composition to be close to the critical composition determined by isocratic experiments. The difference between the composition at elution and the true critical composition for a variety of polymethacrylates and for polyethyleneglycol was found to be only between 0.2 and 5%. Thus, after estimating the composition at elution, only a small number of additional isocratic experiments is needed to find the exact critical composition.     

PLATOP: a novel planarized trench isolation and field oxideformation using poly-silicon

A novel isolation scheme named planarized trench isolation and field oxide formation using poly-silicon (PLATOP) Is described. PLATOP is applicable to high-performance submicron VLSI since it results in encroachment-free shallow trenches, and planarized field oxide. The process offers poly silicon-filled deep trenches. The process also relies on noncritical lithography and novel etch processes to planarize the deposited poly-silicon from the top of the active areas, and oxidation to consume the poly-silicon in the field regions. Electrical results are presented proving the viability of the isolation scheme     

Some pharmacologic and toxicologic studies on Rhazya stricta decne in rats, mice and rabbits

1. This work examines some in vivo and in vitro pharmacologic and toxicologic effects of extracts of Rhazya stricta, a medicinal plant in the United Arab Emirates. 2. R. stricta extracts at doses of 0.1-10 mg reduced the mean arterial blood pressure (MBP) of anesthetized rats in a dose-dependent manner. The depressor effect was partially sensitive to atropine (5 microM). Although the MBP was reduced by 50% by both doses of extracts, the normal electrocardiogram pattern and the heart rate remained unaltered. 3. Acute treatment of rats with the lyophilized extract at doses of 4 g/kg produced a significant rise in insulin concentration. In streptozotocin-diabetic rats loaded orally with glucose (1 g/kg), R. stricta at doses of 8 g/kg produced significant decreases in plasma glucose concentration at 0.5 and 1 h after treatment. 4. Chronic treatment of rats and mice for 28 days with the lyophilized extract of R. stricta did not affect the plasma glucose or insulin concentration or any of the hematological or biochemical indices measured. 5. The extracts of R. stricta (0.5-4 g/kg) dose-dependently decreased the gastrointestinal transit time in mice by 4-50%. 6. The butanolic extract of R. stricta (1 and 2 g/kg) significantly reduced the carrageenan-induced increase in raw paw edema 3 and 4 h after the extract administration. 7. The rectal temperatures of normothermic and pyrexic rats were reduced significantly 0.5 and 1 h after administration of butanolic R. stricta at doses of 1 and 2 g/kg. 8. The butanolic extract of R. stricta at doses of 1 and 2 g/kg significantly increased the reaction time on the hot plate 30 and 60 min after administration to rats. 9. At concentration < 0.05 mg/ml (bath concentration), lyophilized water and butanol extracts of R. stricta potentiated the twitch responses induced by indirect electrical stimulation in the rat phrenic nerve diaphragm preparation. The responses were inhibited by concentrations > 0.05 mg/ml. Neostigmine (2 x 10(-4)M) did not alter these effects of the extracts. 10. R. stricta extracts dose-dependently decreased the force of contraction and heart rate of the isolated rabbit heart. Atropine (1 x 10(-5)M) had no effect on the inhibitory activity of these extracts. The lyophilized water extract (> 10 mg) and butanol extract (> 5 mg) produced irreversible inhibition and disturbances in the force of contraction and heart rate.     

Synthesizing Energy-Efficient Embedded Systems with LOPOCOS

In this paper, we introduce the LOPOCOS (Low Power Co-synthesis) system, a prototype CAD tool for system level co-design. LOPOCOS targets the design of energy-efficient embedded systems implemented as heterogeneous distributed architectures. In particular, it is designed to solve the specific problems involved in architectures that include dynamic voltage scalable (DVS) processors. The aim of this paper is to demonstrate how LOPOCOS can support the system designer in identifying energy-efficient hardware/software implementations for the desired embedded systems. Hence, highlighting the necessary optimization steps during design space exploration for DVS enable architectures. The optimization steps carried out in LOPOCOS involve component allocation and task/communication mapping as well as scheduling and dynamic voltage scaling. LOPOCOS has the following key features, which contribute to this energy efficiency. During the voltage scaling valuable power profile information of task execution is taken into account, hence, the accuracy of the energy estimation is improved. A combined optimization for scheduling and communication mapping based on genetic algorithm, optimizes simultaneously execution order and communication mapping towards the utilization of the DVS processors and timing behaviour. Furthermore, a separation of task and communication mapping allows a more effective implementation of both task and communication mapping optimizationsteps. Extensive experiments are conducted to demonstrate the efficiency of LOPOCOS. We report up to 38% higher energy reductions compared to previous co-synthesis techniques for DVS systems. The investigations include a real-life example of an optical flow detection algorithm.     

Distal dorsal forearm flap

Reinstatement and spontaneous recovery of previously extinguished nicotine-taking behavior were examined in rats. Male subjects were trained to self-administer nicotine (30 microg/kg per infusion, IV; one 60-min session per day for 3 weeks). Extinction sessions were then given for 5-10 days during which saline was substituted for nicotine. Subsequently, in the first set of tests for nicotine seeking, the reinstatement of lever presses that previously delivered nicotine was examined after priming injections of saline and nicotine (75, 150 and 300 microg/kg, SC; and 30 and 60 microg/kg, IV). In the second set of tests for nicotine-seeking, rats were tested after an additional 21-day drug-free period during which they were not exposed to the self-administration chambers (a test for the spontaneous recovery of drug seeking), and after priming injections of nicotine (150 and 300 microg/kg, SC). Reinstatement of extinguished food-reinforced behavior after exposure to nicotine was also determined. Priming injections of nicotine reinstated nicotine seeking regardless of the route of administration. In addition, previously extinguished nicotine seeking recovered spontaneously after a 21-day period during which rats were not exposed to the drug-taking environment. Nicotine also reinstated extinguished food-reinforced behavior in rats with a history of nicotine self-administration, but not in drug-naive rats. The present results extend previous work with opioid and stimulant drugs on reinstatement of drug seeking by the self-administered drug. It also appears that, as with other positive reinforcers, the mere passage of time is a sufficient condition for the spontaneous recovery of extinguished nicotine seeking.     

Novel Organometallic Aromatic Azo Polyesters Based on Ferrocene

Some ferrocene containing aromatic azo polyesters were prepared by condensing 1,1-ferrocenedicarbonyl chloride with different azo groups containing aromatic diols, which were synthesized by diazotization coupling reaction from aromatic diamines. The polymeric products were separated as two portions on the basis of their solubility and subsequently characterized by their elemental analysis and FTIR spectral studies. Thermal properties of the products were measured by differential scanning calorimetry and thermogravimetry and the activation energies of pyrolysis were calculated using Horowitz and Metzger's method. The molecular weights of the soluble portions were determined by gel permeation chromatography (GPC) and these portions were also characterized by their inherent viscosities and UV-Vis spectroscopic studies.     

Positional distribution of CLA in TAG of lamb tissues

The content and positional distribution of CLA in TAG fractions of lamb tissues was examined with either preformed CLA or the linoleic acid precursor of CLA in the diet as experimental treatments. The CLA content of phospholipid (PL) from these tissues was also examined. Thirteen lambs were randomized to the following dietary treatments: (i) control diet (no supplement); (ii) CLA supplementation (0.33 g d⁻¹ for 21 d prior to weaning) to milk-replacer of pre-ruminating lambs, or (iii) feeding linoleic acid-rich oil (6% safflower oil on a dry matter basis) to weaned ruminating lambs. At slaughter, tissue samples were procured from diaphragm, rib muscle, and subcutaneous (SC) adipose tissue. Safflower oil supplementation in the diet resulted in an increase in CLA content of the TAG from diaphragm, rib muscle, and SC adipose tissue by about threefold (P<0.05) on a mol% basis. CLA was localized to the sn-1/3 positions of TAG. Animals that received pre-formed CLA, however, had increased proportions of CLA at the sn-2 position of TAG from SC adipose tissue, suggesting that there were tissue-specific dietary effects and possible age-related effects on the mode of FA incorporation into TAG. Safflower oil supplementation in the diet had no effect on the CLA content of PL from diaphragm, rib muscle, and SC adipose tissue, suggesting that CLA was preferentially incorporated into the TAG of these tissues.     

UV-shielding by a polyurethane/f-Oil fly ash-CeO2 protective coating

A waste material called oil fly ash (OFA) was acid-functionalized, yielding f-OFA-COOH, which was then reacted with cerium oxide (CeO₂) to make CeO₂-functionalized OFA, or f-OFA-CeO₂. Pristine OFA and f-OFA-CeO₂ were used to make waterborne polyurethane (WBPU) dispersions, referred to as WBPU/OFA and WBPU/f-OFA-CeO₂, respectively, with defined OFA and f-OFA-CeO₂ content. All the dispersions were applied to mild steel as organic coatings to evaluate their protective properties, such as their hydrophobicity, adhesive strength and UV-shielding resistance. These protective properties varied based on the OFA and f-OFA-CeO₂ content. The highest water contact angle, minimum water swelling and maximum adhesive strength were found using WBPU/f-OFA-CeO₂-20 coating (using 2.00 wt% f-OFA-CeO₂), which also showed the maximum ultraviolet (UV) absorption via UV–vis spectroscopy analysis. This UV shielding result also matched field test results, as that coating was found to exhibit the lowest UV degradation near a marine atmosphere, as shown by X-ray photoelectron spectroscopy (XPS) analysis. The least affected hydrophobicity was also recorded for the sample with the WBPU/f-OFA-CeO₂-20 coating.